The controversial Keystone XL pipeline moved closer toward approval at the end of January when the US State Department issued a favorable report for the transcontinental project.

But two US senators say that State Department officials failed to consider the human health effects of permitting the 1,700-mile pipeline, which would carry tar sands oil from Alberta to Texas.

“The Final Supplemental Environmental Impact Statement [put out by the State Department] was woefully inadequate regarding human health impacts. . .,” Sens. Barbara Boxer (D-CA) and Sheldon Whitehouse (D-RI) wrote to Secretary of State John Kerry in a letter today.

The letter, which highlighted several health concerns pertaining to the construction and operation of the pipeline, was sent on letterhead from the Senate Committee on Environment and Public Works, which Boxer chairs.

It’s “critically important” that the State Department consider peer-reviewed research on this topic before making a final decision on the pipeline, they wrote.

“We have already seen how communities along each step of the toxic tar sands oil process — from the extraction to the transport to the refining to the waste disposal — will be impacted,” the letter continued.

“Elevated levels of carcinogens and mercury have been documented downstream from tar sands extraction sites, and communities in these areas show elevated levels of rare cancer rates.”

The letter noted that people living downwind of tar sands refineries are “suffering higher rates of the tuypes of cancers linked to these toxic chemicals, including leukemia and non-Hodgkin’s lymphoma.”

They also cited the 2010 tar sands oil spill into the Kalamazoo River as an example of how difficult tar sands oil can be to clean up. The Kalamazoo River remains polluted from the spill, the result of a pipeline break.

The two senators concluded:

“We believe that putting more Americans at risk for asthma, cancer, and other serious health impacts is not in our national interest. Clearly much more needs to be done before any final decision on the Keystone XL pipeline is made, and we urge you to complete a comprehensive human health impacts study — nothing less than the health of our families is at stake.”

Secretary of State has not issued a public response to the senators.

In a related event, an advocate for First Nations people affected by tar sands runoff in Canada, is expected to speak to US senators on the Environment and Public Works Committee. Dr. John O'Connor told the Edmond Journal that he hopes to bring attention to the health ailments that have affected those living near the tar sands mines, including the community of Fort Chipewyan.